Fix small typo in good/bad code sample.

Author: jelaiw

java/ql/src/Security/CWE/CWE-327/BrokenCryptoAlgorithm.java

@@ -7,6 +7,6 @@
 // ...
 
 // GOOD: AES is a strong algorithm
-Cipher des = Cipher.getInstance("AES");
+Cipher aes = Cipher.getInstance("AES");
 
-// ...
+// ...